Hey, thats pretty much what an MBrain is. If we don't have any
materials shortages (I'm kinda worried about copper or niobium for
the SC coils on the Mass drivers). Then we can build a first
approximation MBrain out of Mercury in only a few weeks. The
interesting part of MBrain subunits is whether or not you could
make them light enough to station/orbit manage via sail methods
or whether they will be so heavy (all that coolant circulating...)
that you have to use some inter-node diamond tension cables or
even vector jets to keep the nodes from running into one another.
You have to keep in mind that in order to maximize energy collection
and radiator surface area you want the nodes orbiting "virtually"
edge-to-edge. I don't believe the responses required to deal with
pressures generated by solar flares will be trivial (at least if the
subunits are relatively "light").

Since one of the best ways to dismantle Mercury involves lots of Mass
Drivers, you are going to have the technology to despin, reorient and
cool JBrains, if you want to go that route. I do think the issues of
heat transfer from the JBrain to your coolant stream are being *glossed
over* however. Its one thing to say its an engineering problem, its
another to avoid discussing the existing principles of physics on which
the engineering should be based. There is a fine line between creative
astroengineering and magic physics and one has to be careful not to cross it.